The primary purpose for a contact lens is to correct the focus of an eye by changing the eye's focal length as needed. It has been found that contact lenses offer a second benefit. By providing a colored pattern on the surface of the contact lens, the coloring of the iris of the eye can be changed. This can be beneficial to an individual who finds eye color to be an important feature of an individual's face and believes that a change in eye color would enhance his or her appearance.
Presently, colored contact lenses have a color pattern around the outer circumference of the contact lens with the color pattern including numerous radially oriented multicolored lines, with the pattern of lines duplicating the pattern normally found in the iris of an eye. The central portion of the contact lens which is positioned over the pupil is left uncolored so as not to obstruct the view of a wearer.
It has been found that it is difficult to reproduce the coloring of the human eye and as a result another individual can often detect when one is wearing a colored contact lens. It is therefore desirable to enhance the coloring qualities of the ink applied to colored contact lenses.
A particular problem for the wearer of contact lenses is that it is difficult to tell the convex side from the concave side of the lens. As a result, the wearer can inadvertently apply the lens to the eye in the upside down orientation thereby causing irritation to the eye and complicating the installation process. To minimize the occurrence of reversing the lens, it has become common to provide inversion markings on one side of the lens that would distinguish the convex from the concave side of the lens. Such inversion markers are normally small in size. Where the uncorrected eyesight of the wearer of the contact lens is poor, it may be difficult for him or her to see a small inversion marker on the contact lens. In such cases, the marker is of no value. It would be desirable, therefore, to provide a more readily visible inversion marker.